NASA's James Webb Space Telescope

JWST Science

NASA's James Webb Space Telescope (JWST) will be the most powerful telescope ever launched into space.

Artist's impression of James Webb Space Telescope in space
Artist's impression of James Webb Space Telescope in space.

About the James Webb Space Telescope

The James Webb Space Telescope is NASA's next orbiting observatory and the successor to the Hubble Space Telescope. JWST is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate JWST after launch.

From measuring the composition of other rocky worlds in the Milky Way to seeing the first light from the earliest stars and galaxies, astronomers around the world will use JWST to tackle the biggest questions facing our understanding of the universe. JWST's innovative design and technologies include:​

  • a 21-foot (6.5-meter) primary mirror, built from 18 adjustable segments, to provide the deepest and sharpest images of the cosmos to date
  • a 5-layer, tennis-court-sized sunshield to cool the telescope to 40 degrees above absolute zero
  • four pioneering science instruments with superb performance in the infrared part of the spectrum
  • a deployable design and an observing environment far from any heat sources, 1 million miles from Earth

Webb will detect infrared radiation and be capable of seeing in that wavelength as well as Hubble sees in visible light. Infrared vision is vital to our understanding of the universe. The furthest objects we can detect are seen in infrared light, cooler objects that would otherwise be invisible emit infrared, and infrared light pierces clouds of dust, allowing us to see into their depths.  Webb will unleash a torrent of new discoveries, opening the door to a part of the universe that has just begun to take shape under humanity's observations.

Right now, scientists and engineers are piecing Webb together, creating through cutting-edge technology an innovative observatory that not only withstands intense cold, but uses it to its advantage; an observatory that folds up inside a rocket for launch and unfurls like a butterfly opening its wings upon nearing its orbit. In Spring 2019, the Webb telescope will launch into space, sailing to the distant, isolated orbit where it will begin its quest. Supernovae and black holes, baby galaxies and planets' potential for supporting life — Webb will help reveal the answers to some of the biggest mysteries of astronomy.